The present invention relates to rearview mirror assemblies for vehicles and, more particularly, to a case assembly for a rearview mirror which provides lighting for illuminating selected portions of a vehicle interior and which includes controls for providing such illumination, mounted on the front of the assembly.
Various types of rearview mirror assemblies which provide lighting have been used in the past. One such structure includes a housing secured to the back of a rearview mirror case and having a pair of light assemblies mounted on the housing for insertion into the case, through openings in the case back, so that light is directed downward from the spaced lights. The lighting provided by the structure was appropriate for low level interior courtesy lighting for the front passenger area of a vehicle. However, the housing of this prior mirror assembly wrapped around the case back to the bottom of the case and was, in part, visible by the driver of the vehicle. Moreover, adaptability of this assembly to sophisticated vehicle interior designs was limited.
Subsequent rearview mirror assemblies including lighting as an integral part of the assembly have been developed. Such development commonly involved inserting a miniature lamp assembly into a standard mirror case which had been minimally modified to increase interior volume as required for the lamp assembly. Many such assemblies have developed overheating problems and are commonly expensive devices with fragile control wiring. A common practice for providing electrical current to such prior illuminating mirror assemblies commonly involved a wire raceway extending out of the mirror case for connection with the vehicle electrical power circuit. These wire raceways which extend from the mirror case are subject to twisting and tension, each of which tend to wear and break the raceway and transmit stress to wiring inside the case. Further, the wiring inside the mirror case has commonly employed slip fit connectors at each electrical component. Such connectors are often subject to disconnection because of vibration and other causes, inherent in a vehicle environment.
Such prior assemblies are also commonly susceptible to the development of glare in the mirror element, on the vehicle windshield, and on the vehicle instrument panel, because of the emission of stray or uncontrolled light. As may be well appreciated, such glare creates a safety hazard. In a passenger compartment of a vehicle, it is desirable to minimize, if not eliminate, glare reflecting from the windshield or the instrument panel. Thus, a primary consideration in the design of an illuminating mirror assembly is the containment and direction of light generally away from the windshield and dash areas and toward the laps of the passengers, where the lighting will be most useful.
The present invention was conceived as a solution for and an improvement over the above and other design limitations of prior known lighted rearview mirror structures which provide illumination.
Accordingly, the present invention provides a case assembly for vehicular rearview mirrors adapted to define a compartment on or within the case and, which, in a preferred embodiment is effectively sealed against the back of the mirror element. Preferably, the sealing means also provides an antiscatter function for the mirror element in the event of breakage.
A rearview mirror assembly according to one form of the present invention includes a case having a back wall and a perimeter side wall defining an interior space within the case. Walls extending within the case from the back wall define a compartment within the case. The compartment is connected with the outside of the case through an opening located in a bottom portion of the side wall. A mirror element is supported and retained by the case, opposite from the back wall. A sealant is provided between the compartment walls and the back of the mirror element to seal the compartment and prevent escape of uncontrolled or stray light from the compartment.
In one aspect of the invention, a reflector with a progressive or variable radius of curvature is provided in the compartment for selectively directing light out of the compartment. In another aspect of the invention, the case is adapted to receive electrical components, specifically, controls, light bulb holders and a power plug, for powering a lamp assembly positioned in the compartment. The electrical components are mounted to the housing for improved durability and reliability of the control wiring system. Specifically, a power plug connects the mirror assembly with the vehicle electrical system and the power plug is mounted in the back wall of the case of the mirror assembly. A switch is provided in the mirror assembly and also mounted to the case for controlling the electrical current to and thus illumination of the lamp assembly. Finally, the electrical components, i.e. the power plug, the switch, and the lamp assembly, are directly connected, one with another, by wiring, without intermediate connectors.
In yet another aspect of the invention, a lens is mounted in the side wall opening to refract and reflect light projected from the lamp assembly, away from the windshield and instrument panel of a vehicle in which the assembly is mounted. In a further aspect of the invention, the compartment on or within the case is ventilated to dissipate heat from the compartment. The lens and opening define a ventilation passage between the lens and the case for the flow of air from outside the case, around the lens, and into the compartment. A ventilation hole or passage in the back of the mirror case and communicating with the compartment is also provided. A ventilation conduit, positioned generally opposite the compartment from the lens, may also be provided and extends from the compartment to outside the case. A light baffle or maze is formed by the conduit so that light may not escape from the compartment through the ventilation conduit.
The rearview mirror assembly of the present invention provides an improvement over the prior art with a simplified and more durable lighting assembly. Many of the electrical interconnections which are used in previous control wiring systems have been eliminated in the present mirror assembly to enhance durability. Improved sealing of stray or uncontrolled lighting is also accomplished in the present assembly. Further, enhanced control of the distribution pattern of light projected from the assembly is provided by unique reflector usage and design and by unique lens design. Also, improved ventilation of the lighting assembly is also provided. All of this is accomplished in a lighter weight and less expensive assembly because of the simplification of the present assembly over the prior art.